After restarted libvirtd service, live migration VM hit an issue 'Target CPU check default does not match source none'

Hi All, After restarted the libvirtd service on the source host, we start live migration VM to destination host and often hit an issue 'unsupported configuration: Target CPU check default does not match source none’ We don’t configure any special setting for CPU model when start VM and I think it should be ‘custom’ mode by default . Furthermore , those two hosts for doing live migration have almost the same capabilities as below. It’s confused me why failed to check the cpu configuration after restart libvitd service on source host? The libvirt version is 7.9.0, package: 1.el8 (Unknown, 2021-11-28-22:35:11) private build Host OS version : rhat8.4 QEMU version: QEMU 5.1 private build Any comments are appreciated. Thanks